Image processing tools for the validation of CryoEM maps.

The number of maps deposited in public databases (Electron Microscopy Data Bank, EMDB) determined by cryo-electron microscopy has quickly grown in recent years. With this rapid growth, it is critical to guarantee their quality. So far, map validation has primarily focused on the agreement between maps and models. From the image processing perspective, the validation has been mostly restricted to using two half-maps and the measurement of their internal consistency. In this article, we suggest that map validation can be taken much further from the point of view of image processing if 2D classes, particles, angles, coordinates, defoci, and micrographs are also provided. We present a progressive validation scheme that qualifies a result validation status from 0 to 5 and offers three optional qualifiers (A, W, and O) that can be added. The simplest validation state is 0, while the most complete would be 5AWO. This scheme has been implemented in a website https://biocomp.cnb.csic.es/EMValidationService/ to which reconstructed maps and their ESI can be uploaded.

[Identification of anomalous coronary arteries and their anatomic course by multidetector computed tomography coronarography. A retrospective registry]. / L'utilisation du scanner cardiaque multibarrettes pour l'exploration des anomalies coronaires. Analyse d'une série rétrospective monocentrique.

BACKGROUND: The coronary anomalies are generally asymptomatic and rare. However, their potential complications are serious and mainly represented by the risk of sudden death. The coronarography appears insufficient to carry out the complete assessment of these anomalies, and in particular to study the arterial course. The endpoint of our series is to evaluate the interest of the coronary computed tomography (CT) in this indication. PATIENTS AND METHODS: We report the results of a 16-slice coronary-CT monocentric retrospective series among 12 patients presenting coronary anomalies diagnosed in coronarography. RESULTS: Coronary-CT has confirmed the diagnosis, specified the coronary course and the relation with the great vessels in 100% of the cases. CONCLUSIONS: Multislice coronary-CT seems an examination of choice for the diagnosis and the presurgical assessment of the coronary aberrations, like for the distinction of the benign and malign forms. Its effectiveness and its "non-invasive" character are strong arguments to include it in the assessment of syncopes linked to effort in the young adult.

[Multidetector computed tomography coronarography: preliminary experience in real life settings]. / Scanner coronaire: bilan d'une expérience préliminaire dans le cadre de la vraie vie.

UNLABELLED: Multidetector computed tomography coronarography (MDCT) is a promising tool, offering non invasive anatomic evaluation of coronary arteries. We relate in this article our impressions after our first two years experience. METHODS: Retrospective study of the 328 patients who underwent MDCT examination between January 2005 and December 2006 at our community hospital. Per patient comparative analysis of the anatomical findings versus percutaneous angiography (PCA) in 61 cases. RESULTS: Out of 328 patients 61 (18.5%) underwent PCA. In these patients we found a sensibility, specificity, positive predictive value and negative predictive value of 100%, 54%, 59% and 100% for MDCT. The main factor responsible for inconclusive vessel analysis was excessive calcification. CONCLUSION: In routine use, MDCT enables one to rule out significant stenosis non invasively, with high sensitivity in an unselected patient population.

CT-anatomic correlations of the normal capsulo-ligamentous bands of the extrinsic joints of the thoracic spine.

Five anatomic specimens were studied in an attempt to visualize by high-resolution computed tomography (HRCT) the ligamentous bands of the costotransverse and costovertebral joints. HRCT-anatomic comparison is presented to relate the CT views to the anatomic structures. The authors demonstrate that axial, sagittal and, to a lesser extent, coronal HRCT views perfectly outline the ligamentous structures, although these are flattened, short, deep and free from calcium deposit. The method may be valuable in disease states such as ankylosing spondylitis.

Section of the odontoid process by a shortened transverse ligament (a possible etiology for the mobile odontoid).

The authors propose a theory concerning the pathogeny of the mobile odontoid. They believe that this malformation could result from abnormal shortness of the transverse ligament of the atlas.

[Radiological aspects of cerebral and spinal cysticercosis. Apropos of 2 cases]. / Aspects radiologiques de la cysticercose cérébrale et rachidienne. A propos de 2 observations.

Two cases of neurocysticercosis are reported, one cerebral and the other spinal. Results of radiologic imaging of this affection, a rare parasitosis in occidental Europe, are discussed with emphasis on computed tomography findings. In fact, when perfect conditions can be established the CT scan provides data confirming the diagnosis of cerebral cysticercosis in most cases. However, this scan is insufficient for investigation of ventricular or cisternal forms when gas or positive contrast is sometimes necessary for visualization of parasitic cysts. Radiologic diagnosis of extra- and intra-medullary forms is based an myelography with water-soluble contrast completed by a scan.

CT of the main ligaments of the cervico-occipital hinge.

The results of a CT-anatomical correlative study of the main ligaments of the cervico-occipital hinge are reported. CT criteria of normal ligamentous structure of this region are presented in axial, coronal and sagittal views with a special attention to the transverse ligament of the Atlas. Examples of pathological transverse ligaments are illustrated and emphasis is laid upon the better statement CT allows in such cases.

Sacral meningeal arteriovenous fistula fed by branches of the hypogastric arteries and drained through medullary veins.

The authors report a new case of intraspinal extra-medullary meningeal arteriovenous fistula draining through medullary veins. Discovered in a 33-year-old black man suffering from a cauda equina syndrome, this malformation suspected in myelography was confirmed by a selective angiographic procedure of both internal iliac arteries. This investigation specified the sacral site of the fistula as well as its feeding arteries from several branches of the left and right internal iliac arteries and its posterior and intra-meningeal venous medullary drainage. An embolization procedure followed by a surgical approach and a second embolization session brought a fair improvement to this young patient who could walk again. The acquired traumatic origin of the fistula is discussed for this patient who had been previously operated at his L5-S1 level.

[Headache of cervical origin]. / Kopfschmerzen zervikaler Genese.

The authors recall cervical etiologies of headache. They distinguish on the one hand the cervico-occipital region with minor and major malformations and acquired lesions, and on the other hand the middle and inferior cervical segment. They also recall the original structuralist analysis of the cervical spine and give the example of the "cervical triplet".

CT findings in malignant meningiomas.

Recurrent meningiomas are due usually to incomplete removal as in the case of basal meningiomas where the tumour surrounding vessels and nervous structures cannot be completely excised. Recurrent meningiomas of the convexity are rare after resection. In most recurrent cases histological changes are noted which may explain the rapid growth, the aggressive nature and also the malignancy of the tumour. These changes include increased mitotic activity, necrosis and invasion of the adjacent brain parenchyma. CT findings in malignant meningiomas are related to the microscopic appearance of these tumours: tumoral necrosis determines heterogeneous enhancement; brain invasion explains the irregular outline of the tumour and sometimes the absence of surrounding low attenuation area. The authors report 5 malignant meningiomas in which the CT findings are correlated with the microscopic findings.